Modification of thermal and rheological characteristics of bitumen by waste PET/GTR blends

- Waste PET/GTR blends obtained via melt-compounding were used as bitumen modifiers.
- Performance properties of modified bitumen depends strongly from composition and content of wPET/GTR blends.
- wPET/GTR blends improved rheological properties and thermal stability of bitumen.

Waste poly(ethylene terephthalate) (wPET)/ground tire rubber (GTR) blends with variable compositions were applied as low-cost modifiers into bitumen and their performance has been evaluated via morphological, thermal and rheological analyses. Depending on the weight ratio of wPET/GTR, dispersion of single/composite domains of waste polymers in the bitumen has promoted the interaction between bitumen and blend components. Fourier transform infrared spectroscopy confirmed an adequate physical interaction between bitumen and wPET/GTR blend, while morphological analyses suggested deterioration of interaction upon increase of GTR content, which can be ascribed to the cross-linked structure of GTR. Increasing wPET/GTR content led to an improved rheological properties and thermal stability of the bitumen, especially for wPET/GTR blends composed mainly of wPET due to its thermoplastic character. The present work indicates that rheological and thermal properties of bitumen can be satisfactorily modified varying composition and content of wPET/GTR in the bitumen matrix.